JP2862347B2 - Printing machine dampening water supply apparatus and printing machine dampening water supply method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a dampening solution supply device for a printing press and a dampening solution supply device for a printing press applied to a dampening solution supply for an offset printing press of a lithographic printing press. About the method.

[Conventional technology]

As is well known, in a lithographic printing press, it is necessary to keep the supply amounts of ink and dampening solution within an appropriate range in order to obtain good printed matter. For example, if the supply amount of the dampening solution is too small with respect to the ink supply, the ink adheres to the image area as well, and so-called stains (Filling in at shadow dot portions, background stains, etc.) occur. Conversely, if the dampening solution supply is excessive, water loss occurs, such as poor print density or water marks due to poor ink transfer. Currently, generally, operators regularly check the finish of printed matter and the degree of wetness of the plate surface. Monitoring and evaluation, the dampening water supply is being increased to maintain the appropriate range. The operator is always kept away from the machine for this monitoring and requires skill for monitoring. Therefore, attempts have been made to automate the adjustment of the dampening solution supply amount, aim at labor saving of the operator, non-skilling and stable printing quality. JP-B-57-182622, JP-B-58-153655, JP-B-58-217355, JP-B-59-156754, JP-B-59-211830, and JP-B-61-89047 are the trials.

They differ in details, but generally:

FIG. 5 shows the external structure of the plate cylinder of one printing unit of a lithographic printing press.

In FIG. 5, a water film thickness meter 1 capable of measuring a dampening water film adhering to a non-image area of the mounted plate 8 on the outer periphery of the plate cylinder 9 is shown.
Is installed. The water film thickness meter 1 is capable of quantitatively measuring the water film thickness based on the degree of absorption of infrared light and the degree of reflection of laser light, which change depending on the size of the water film thickness. It can be moved and set at any position in the width direction.

Further, by providing a rotary encoder in the plate cylinder driving system, the water film thickness can be detected at a predetermined position on the circumference. The detection signal of the detected water film thickness is taken into the control device 7 and compared with a preset optimum water film thickness, that is, a target water film thickness. If there is a difference between them, a control signal for making the difference zero, that is, a signal for increasing or decreasing the number of rotations of the water supply roller 5 is given to the electric motor 6. Thereby, the water film adhering to the non-image area of the plate 8 can be automatically kept at an appropriate value.

As described above, if the water film thickness of the non-image area of the printing plate, which is free from stains and has a print density inadequate or without a water mark, is always constant, as described above, the optimum water film always fixed in advance. The thickness, that is, the target water film thickness may be maintained.

However, in practice, the appropriate water film thickness changes depending on the temperature and humidity around the ink roller group, the printing speed, and the ink supply amount.

As an actual example, FIG. 3 shows a measurement example of a change in an appropriate water film thickness due to the temperature and humidity around the ink roller group. As described above, there is a problem that dirt and a water mark are generated even though the control is performed due to the change in the appropriate water film thickness.

Therefore, temperature and humidity in the ink roller group, ink supply amount,
The change amount of the optimum water film thickness due to the printing speed and the like is grasped by experiments, and a prediction formula of an appropriate water film thickness is created. The control device estimates an appropriate water film thickness based on the prediction formula, compares the estimated water film thickness with the detected water film thickness, and if there is a difference between the two, a control signal to make the difference zero. Send to dampening water supply.

Thus, even if the factors that change the appropriate water film thickness, such as the temperature and humidity around the ink roller group, change during control, the target water film thickness is automatically corrected accordingly. The generation of dirt and water marks can be prevented.

[Problems to be solved by the invention]

Even if factors that change the appropriate water film thickness, such as temperature and humidity around the ink roller group, change during control, the target water film thickness is automatically corrected in accordance with this change. Occurrence can be prevented.

However, in practice, when the machine is started up, dampening water is not supplied to the ink roller group and the plate surface, and waste paper occurs until the water film thickness becomes appropriate.

As an actual example, FIG. 4 shows an example of measurement of a change in the film thickness of the dampening solution adhering to the non-image portion of the plate mounted on the outer periphery of the plate cylinder at the time of starting the machine. As described above, due to the change in the water film thickness, despite the control using the conventional method,
There is a problem that dirt and water marks are generated.

The present invention has been made in view of the above circumstances, and a dampening water supply device for a printing press capable of appropriately adjusting the water film thickness on a printing plate not only at the time of machine steady operation but also at the time of machine startup. And a method for supplying a dampening solution for a printing press.

[Means for solving the problem]

In order to improve the above disadvantage, the present invention provides a dampening solution supply device for a printing press and a dampening solution supply method for a printing press as described below.

That is, a dampening solution supply device for a printing press according to claim 1, wherein a plate cylinder for mounting a plate on an outer periphery, an ink application roller detachable from the plate, and an ink kneading roller group in contact with the ink application roller. And a swimsuit roller detachable from the plate, a bypass roller detachable from the inking roller and the swimsuit roller, and ink on the plate via the ink mixing roller group and the inking roller. Ink supply means for supplying, and dampening water supply means for supplying dampening water to the plate via the swimsuit roller, wherein the ink application roller is removed from the plate, and the swimsuit roller is When the bypass roller is attached to the plate, and the bypass roller is attached to the inking roller and the swimsuit roller, the dampening solution supply means supplies the swimsuit roller and the bypass roller. Through fine the ink form roller is characterized by being configured to supply the dampening water on the ink distribution roller group and the plate.

The fountain solution supply device for a printing press according to the second aspect is the first aspect.
In the fountain solution supply device for a printing press described above, a means for detecting a rotation speed of the plate cylinder, a means for detecting a temperature and a temperature near the ink mixing roller group, a means for detecting an ink supply amount, and Means for detecting the water film thickness on the plate movably mounted in the width direction of the plate cylinder, means for calculating the optimum water film thickness from the rotation speed, temperature, humidity and ink supply amount; Means for comparing and calculating the water film thickness and the water film thickness on the plate; means for automatically attaching / detaching the ink application roller, the swimsuit roller and the bypass roller based on a result of the comparison operation; Means for controlling the dampening solution supply means based on the result of the calculation.

A fountain solution supply method for a printing press according to claim 3, wherein a plate cylinder for mounting a plate on an outer periphery, an ink application roller detachable from the plate, and an ink mixing roller group in contact with the ink application roller; A swimsuit roller detachable with respect to the plate, a bypass roller detachable with respect to the ink application roller and the swimsuit roller, and ink supplied to the plate via the ink mixing roller group and the ink application roller. A dampening solution supply method for a printing press, comprising: an ink supply unit; and a dampening solution supply unit that supplies dampening solution to the plate via the swimsuit roller. The swimsuit roller is attached to the plate, the bypass roller is attached to the inking roller and the swimsuit roller, and the dampening solution supply means is provided through these rollers. And supplying dampening water to the ink mixing rollers and the plate, and then, after the water film thickness on the plate reaches a predetermined thickness, setting the ink forming roller to the plate. It is characterized by.

(Operation)

In the dampening solution supply device for a printing press according to the present invention, before the printing is started, the bypass roller is brought into contact with the swimsuit roller and the ink application roller, so that the dampening solution is supplied to the ink mixing roller group and the plate surface by the dampening solution supply means in advance. Supply water. At this time, the optimum water film thickness is compared with the detected water film thickness on the plate, and if there is a difference between them, a control signal for making the difference zero is sent to the dampening solution supply means. Then, when the water film thickness on the plate has become an appropriate thickness, send a control signal,
The inking roller is worn, and then the bypass roller is removed. Thereafter, a sheet pass signal is given to start printing.

Thereafter, a signal is supplied to the dampening water supply means so as to make the deviation between the water film thickness on the plate surface and the optimum water film thickness zero as described above, and the water supply amount is automatically controlled.

When the machine is started up by the above means, dampening water is supplied in advance from the dampening water supply means to the ink mixing roller group and the plate surface, and the water film thickness on the plate surface is equal to the target plate water film thickness. Therefore, it is possible to prevent the occurrence of stains and water marks at the start of printing in the related art.

〔Example〕

One embodiment of the present invention will be described with reference to FIG. A water film thickness meter 1 capable of measuring fountain solution adhering to the non-image area of the plate 8 after the end of contact with the final inking rollers 14a, 14b, 14c, 14d is installed similarly to the conventional one. You. This water film thickness meter 1
Is moved on the guide rail 10 by a moving device (not shown) and is fixed at an arbitrary position in the width direction. Since the place where the ink supply amount is the largest in the width direction requires the largest amount of dampening solution, the position where the ink supply amount is the largest in the width direction, that is, the image area ratio is usually fixed. Also, if the setting is made such that the water film thickness is always measured only in the region from the end position of the pattern to the notch start position A by using a rotary encoder for the plate cylinder drive system, etc. There is no need to recognize the distinction, and the system becomes simple.

In addition to the water film thickness meter 1, a thermo-humidity meter 2 for measuring the temperature and humidity around the ink mixing roller group is installed near the ink roller group. A tachometer 3 for detecting the printing speed.
Is installed, the number of rotations of the plate cylinder 9 is measured, and the gap δ between the ink source roller 16 and the ink scraping blade 17 is measured by the displacement meter 4 to detect the ink supply amount. The detected water film thickness, the temperature and humidity surrounding the ink roller group, the printing speed, and the signal of the ink supply amount are taken into the control device 7. The controller 7 first calculates the appropriate water film thickness tT experimentally obtained in advance from the temperature and humidity around the ink mixing roller group, the ink supply amount, and the printing speed.

Next, the detected water film thickness tA is compared with the proper water film thickness tT. If there is a difference between the two, a control signal for reducing the difference to zero, that is, a rotation speed increase / decrease signal of the water supply roller 5 To the water roller drive motor 6 to automatically adjust the number of rotations of the water roller 5.

The above is the control during the normal printing except when the machine is started. However, the control when the machine is started will be described with reference to FIG. First, the ink applying rollers 14a, 14b, 14c and 14d are detached from the printing plate 8, and the bypass roller 11 is connected to the ink applying roller 14d.
Then, it is put on the wetting roller 12. The watering roller 12 is attached to the plate 8. Thereby, the dampening water is supplied onto the ink mixing roller group 13 and the plate 8, and the water film thickness on the plate 8 is maintained at an appropriate plate surface water film thickness. At the same time that the water film thickness on the plate 8 becomes the appropriate plate surface water film thickness, the control device 7 gives an ink forming roller mounting signal 19 to the ink forming roller attaching / detaching device 18 to control the ink forming rollers 14a, 14b, 14c, 14d. Dress up against version 8,
At the same time, a bypass roller release signal 21 is given to the bypass roller attaching / detaching device 20, and the bypass roller 11 is connected to the ink applying roller.
8 and d and the wetting roller 12. After the above control, the control device 7 sends a sheet pass signal 21 to the printing press to start printing. However, the bypass roller 11 is used to prevent the printing trouble (water droplets and the like) from occurring.
There is also a case where printing is performed on the swimsuit roller 12 and 4,4d while wearing.

〔The invention's effect〕

According to the dampening solution supply device for a printing press of the present invention, the inking roller is detached from the plate, the swimsuit roller is attached to the plate, and the bypass roller is the inking roller. And when it is worn on the swimsuit roller, the dampening water supply means dampens and supplies the ink on the ink mixing roller group and the plate via the swimsuit roller, the bypass roller, and the ink application roller. Therefore, the following effects are obtained.

It is possible to supply the dampening water to the ink mixing roller group and the plate surface from the dampening water supply means via the bypass roller in advance at the time of starting the machine, as well as stabilizing the printing quality in the steady operation. The water film thickness on the plate surface at the time of startup can be appropriately adjusted. In addition, the water film thickness on the plate surface can be made to coincide with the target water film thickness, and the problem of dirt and water marks caused by emulsification instability at machine start-up in the prior art can be eliminated.

According to the dampening solution supply method for a printing press of the present invention, before starting printing, the ink applying roller is removed from the plate, the swimsuit roller is attached to the plate, and the bypass roller is connected to the plate. A dampening solution is supplied to the ink forming roller group and the plate from the dampening solution supply means via these rollers, so that the water film thickness on the plate is reduced. After reaching a predetermined thickness, the ink applying roller is attached to the plate, so that the water film thickness on the plate before printing is started can be kept at an appropriate plate surface water film thickness. Therefore, generation of dirt and water marks can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic layout diagram of a waste paper reduction apparatus according to an embodiment of the present invention, FIG. 2 is a diagram showing control at the time of starting up a machine, and FIG. FIG. 4 is a diagram showing a change in the water film range, FIG. 4 is a diagram showing a change over time in the water content on the ink roller when the machine is started up, and FIG. 5 is a schematic layout diagram showing a conventional water amount control device. DESCRIPTION OF SYMBOLS 1 ... Water film thickness gage 2 ... Temperature / humidity gage 3 ... Tachometer 4 ... Displacement gage 5 ... Water source roller 7 ... Control device 9 ... Plate cylinder 11 ... Bypass roller 12 …… Swimsuit roller, 13… Ink mixing roller 14 …… Ink application roller

Continuation of the front page (56) References JP-A-63-27259 (JP, A) JP-A-54-114309 (JP, A) JP-A-58-153655 (JP, A) JP-A-55-57464 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41F 7/24-7/36 B41F 31/02-31/30 B41F 33/10

Claims (3)

(57) [Claims] 1. A plate cylinder for mounting a plate on its outer periphery, an ink application roller detachable from the plate, an ink mixing roller group in contact with the ink roller, and a swimsuit roller detachable from the plate. A bypass roller that is detachable from the ink application roller and the swimsuit roller; an ink supply unit that supplies ink to the plate via the ink mixing roller group and the ink application roller; And dampening solution supply means for supplying dampening solution to the printing plate.The inking roller is removed from the printing plate, the swimsuit roller is mounted on the printing plate, and the bypass roller is When the ink is applied to the inking roller and the swimsuit roller, the dampening solution is supplied from the dampening solution supply means through the swimsuit roller, the bypass roller, and the inking roller. A dampening water supply device for a printing press, which is configured to supply dampening water to a kneading roller group and the plate. 2. A means for detecting the number of rotations of the plate cylinder, a means for detecting temperature and humidity near the ink mixing roller group, a means for detecting an ink supply amount, and a means for moving the plate copper in the width direction. Means for detecting the water film thickness on the printing plate mounted on the printing plate, means for calculating an optimum water film thickness from the rotation speed, temperature, temperature and ink supply amount, Means for comparing and calculating the above water film thickness, means for automatically attaching and detaching the inking roller, the swimsuit roller and the bypass roller based on the result of the comparison operation, and based on the result of the comparison operation 2. A dampening solution supply device for a printing press according to claim 1, further comprising means for controlling said dampening solution supply means. 3. A plate cylinder on which a plate is mounted on the outer periphery, an ink application roller detachable from the plate, an ink mixing roller group in contact with the ink roller, and a swimsuit roller detachable from the plate. A bypass roller that is detachable from the ink application roller and the swimsuit roller; an ink supply unit that supplies ink to the plate via the ink mixing roller group and the ink application roller; A dampening solution supply means for supplying a dampening solution to the plate by means of a dampening solution supply means for supplying a dampening solution to the plate. A swimsuit roller is attached to the plate, the bypass roller is attached to the ink application roller and the swimsuit roller, and the dampening water supply means passes through these rollers to form the ink mixing roller group. And supplying a dampening solution onto the plate, and after the water film thickness on the plate reaches a predetermined thickness, the ink applying roller is attached to the plate. How to supply dampening water.